This invention relates to cleaning heads, for use with or as part of an apparatus for cleaning a surface by application of a cleaning liquid to the surface and removal of the cleaning liquid from the surface by suction.
More particularly, the invention relates to such cleaning heads suitable for use in such cleaning of floor surfaces which are of a relatively unyielding and non-absorbent nature. Examples of materials commonly used for floors or floor coverings, and affording surfaces of the type with which the invention is intended to be used, comprise plastics materials, e.g. vinyl, in the form of a large sheet or small portions constituting "tiles" laid on an underlying supporting surface; ceramic materials, e.g. glazed or unglazed tiles; rubber based materials; or wood, cork or concrete if the surface is sealed with a suitable coating to prevent or reduce absorption of liquid.
There have been many proposals for apparatus for cleaning such surfaces by the application of a cleaning liquid thereto and removal of such liquid, together with dirt removed thereby from the surface, by suction. The cleaning liquid may be water containing a suitable detergent. Cleaning heads for such apparatus, which may be provided as part of single-purpose cleaning appliances or as accessories for multi-purpose cleaning appliances of the suction cleaner ("vacuum cleaner") type, usually include means for distributing the cleaning liquid on to the surface to the cleaned, at least one passage arranged to be connected to a source of suction and having at least one opening arranged to collect liquid from the surface being cleaned, and means for agitating the cleaning liquid whilst in contact with the surface to assist the action thereof in removing dirt from the surface. The agitating means typically comprises at least one brush, a sponge or mop element, e.g. of suitable plastics or rubber foam or cellular material, or a combination thereof.
A cleaning head for such cleaning, and an appliance incorporating the head, are disclosed in our International patent application, Publication No. WO94/06342.
Such cleaning heads cannot normally be used for cleaning surfaces by picking up dry material, particularly from carpeted or upholstered surfaces, without the application of a cleaning liquid, and where an appliance is intended to be used both for wet and for dry cleaning operations, it has been the practice in the past to provide separate and interchangeable heads to perform the respective functions.
This naturally adds to the overall cost of manufacture.